Instant Hot Water Systems
Endless hot water on demand for Australian homes. Compare gas continuous flow and electric instantaneous systems from Midea and Stiebel Eltron, matched to your household and delivered nationwide.
- Endless hot waterHeats on demand, never runs out
- Compact wall unitsFrees floor space vs storage tanks
- Fast Australia-wide deliveryFree freight, dispatch same day
- Sized for your householdFree advice on flow & kW
Stiebel Eltron DHCE6/50 Electric Instantaneous Water Heater
Stiebel Eltron DHCE8/60 Electric Instantaneous Water Heater 9.5kW Single Phase 60 Degrees
Stiebel Eltron DHE 27 AU Electric Instantaneous Water Heater 28kW
Midea M Series M20 20L/min Continuous Flow Gas Hot Water Heater
Stiebel Eltron DHE18 AU 19.4kW 3 Phase Electric Instantaneous Water Heater
Stiebel Eltron DEL18 Plus AU Electric Instantaneous Water Heater 19.4kW 3 Phase
Stiebel Eltron DEL 27 Plus AU 28kW 3 Phase Electric Instantaneous Water Heater
Stiebel Eltron DEL13 Plus AU 14.5kW 3 Phase Instantaneous Electric Hot Water Heater
Stiebel Eltron DHCE8/50 Electric Instantaneous Water Heater 9.5kW Single Phase
Stiebel Eltron HOT 2.6 N Electric Under Sink Boiling Unit
Midea M Series M26 26L/min Continuous Flow Gas Hot Water Heater
Stiebel Eltron LCD 19.4kW 3 Phase Instantaneous Electric Water
Midea M Series M20 20L/min Continuous Flow Gas Hot Water Heater - 70C Preset
Midea M Series M26 26L/min Internal Continuous Flow Gas Hot Water Heater
Midea M Series M26 26L/min Continuous Flow Gas Hot Water Heater - 70C Preset
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Instant hot water systems built for Australian homes
An instant hot water system heats water only when you turn on the tap, so you get endless hot water on demand without the standing losses of a storage tank. Waternex supplies both gas continuous flow and electric instantaneous hot water systems, sized from compact single-bathroom units through to whole-house models for 3 or more bathrooms. Every unit ships free Australia-wide with dispatch usually the same business day.
Types of instant hot water systems we stock
Gas continuous flow hot water systems
Gas continuous flow units are the standard for Australian homes with mains natural gas or LPG. They deliver higher flow rates than most electric alternatives, meaning multiple hot taps can run at once without dropping temperature. Our Midea M Series range covers 20L/min for average households and 26L/min for large households or homes with multiple bathrooms, including a 70°C preset variant for commercial applications and an internal-install model.
Electric instantaneous hot water systems
Electric instantaneous systems are ideal where gas isn't available, for point-of-use installs (kitchen, granny flat, ensuite), or for homes moving off gas. Our Stiebel Eltron German-engineered range spans compact single-phase 9.5kW units for one tap through to whole-home 28kW three-phase models. All are wall-mounted, quiet, and need no flue.
Instant vs storage: which is right for you?
An instant hot water system saves on running cost because it never keeps a tank warm 24/7, and it never runs out of hot water in the middle of a shower. It's ideal for homes with variable hot water demand, holiday houses, and anyone tired of cold showers when the tank runs empty. A storage system is still a fair pick if you have very consistent all-day demand and cheap off-peak electricity, but for most modern households the on-demand approach wins on running cost and comfort.
How to choose the right instant hot water system
Three questions decide which unit you need:
- How many bathrooms and simultaneous hot taps? One bathroom is fine on 15-20kW electric or 20L/min gas. Two bathrooms need 20L/min gas or 19-24kW electric. Three or more bathrooms call for 26L/min gas or 27-28kW three-phase electric.
- Gas or electric? If you have mains gas or LPG, gas continuous flow is usually cheaper to run for high daily volume. If you're all-electric or off-grid with solar, an electric instantaneous unit is simpler and more compact.
- What's your inlet water temperature? Cold Victorian and Tasmanian winter mains water reduces effective flow. Down south, upsize by one bracket to keep shower temperatures comfortable in July.
Still not sure? Send us your bathroom count, gas or power supply and postcode, and we'll spec it in an email, usually the same business day.
Trusted instant hot water brands
We only stock brands that hold up in Australian conditions and have proper local parts support:
- Midea M Series - one of the world's largest hot water appliance makers, backed by a full Australian parts and warranty network. Sharp value for gas continuous flow.
- Stiebel Eltron - German-engineered instantaneous electric hot water, made in Europe, industry benchmark for reliability and control accuracy.
Why buy your instant hot water system from Waternex
- Real advice, not a sales script. Talk to someone who knows the difference between 20L/min and 26L/min before you buy.
- Free Australia-wide delivery. Every unit ships free with same-day dispatch on VIC, NSW and QLD orders placed before 12pm.
- Genuine stock. All products are new, current-model and covered by full manufacturer warranty in Australia.
- Price match guarantee. Found the same unit cheaper elsewhere? We'll beat it.
Frequently asked questions about instant hot water systems
Do instant hot water systems really give unlimited hot water?
Yes, as long as the demand doesn't exceed the unit's flow rate. A 26L/min unit can run two showers plus a kitchen tap at once. A 20L/min unit is fine for a shower plus one basin. Match the unit to your peak simultaneous use and you'll never run out.
Do I need a licensed plumber and electrician to install?
Yes - both gas and electric instant hot water systems must be installed by licensed trades. For gas units you'll need a licensed gasfitter, for electric units a licensed electrician. This is required by Australian law and to preserve the manufacturer warranty.
Are they cheaper to run than a storage hot water tank?
For most households, yes. Because they only heat when you turn on the tap there are no standing losses (the heat that leaks slowly from a warm storage tank). Actual savings depend on your usage pattern and energy tariff.
What size do I need for my house?
As a rough guide: 20L/min gas or 15-20kW electric for one bathroom, 20-26L/min gas or 19-24kW electric for two bathrooms, 26L/min gas or 27-28kW three-phase electric for three or more bathrooms. Colder climates should size up one bracket.
Can an instant hot water system run off solar power?
Electric instantaneous units draw a lot of power for a short time (up to 28kW at peak), so they don't pair naturally with solar exports. Gas continuous flow uses only a few watts of electronics power, so it's a much better fit for solar-powered homes because it barely draws from your inverter.